JPH0124593Y2 - - Google Patents

Description

[Detailed description of the invention] This invention is an electronic digital scale with an auto-zero function, and the auto-zero control of the electronic digital scale enables the tare operation even when the weight of the tare is within the operating range of the auto-zero function. It is related to the device.

In conventional electronic digital scales with an auto-zero function, for example, in order to prevent the display from flickering when no object is placed on the weighing platform, the display is not displayed for weights within a predetermined range. A method is used to automatically set it to zero.

However, this type of electronic digital scale with an auto-zero function has the disadvantage that if the weight of the tare bag falls within the operating range of the auto-zero function, the auto-zero function will be activated and the tare subtraction operation will not be possible. For this reason, in the conventional device, the auto-zero function must be stopped by operating the auto-zero release switch, and then the tare weight subtraction operation must be performed, which is very troublesome to operate.

This invention was made in order to eliminate the above-mentioned drawbacks, and provides an auto-zero control device for an electronic digital scale that enables tare subtraction even when the weight of the tare is within the operating range of the auto-zero function. The purpose is to

This invention will be explained below with reference to embodiments shown in the drawings. The figure is a block diagram showing the configuration of an electronic digital scale with an auto-zero function to which this invention is applied, and reference numeral 1 in the figure is a weight detector that detects the weight of the object to be weighed. The weight detector 1 detects the weight of an object to be weighed, and uses, for example, a load cell or the like to convert the weight of the object into a voltage proportional to the weight of the object. The converted voltage is supplied to the A/D conversion circuit 2, where it is converted into a digital signal, and then supplied to the weight register 3, where it is temporarily stored. The contents temporarily stored in this weight register 3 are supplied to one input terminal of a net weight calculation circuit 4 and are also transferred to a tare register 6 via a gate 5.
The contents of the tare register 6 are supplied to the display section 8 via the gate 7 and also to the other input terminal of the net weight calculation circuit 4.

The output of the net weight calculation circuit 4 is supplied to the net weight register 11 via the auto-zero circuit 10 or directly to the net weight register 11 under the control of the gate circuit 9. The auto-zero circuit 10 has a circuit that determines the weight within the range in which the auto-zero function operates, and has a function of setting the output to zero for weights within this range. The net weight calculation circuit 4 performs an operation of subtracting the stored contents of the tare register 6 from the stored contents of the weight register 3. The stored contents of the net weight register 11 are supplied to the display unit 8 via the gate 7 and also to one input terminal of the charge calculation circuit 12. On the other hand, by operating a unit price setter 13 for setting the unit price per unit weight of the object to be weighed, the set unit price is entered into the unit price register 14 and temporarily stored. The content is supplied to the display unit 8 via the gate 7, and is also supplied to the charge calculation circuit 12.
is supplied to the other input end of the . The fee calculation circuit 12 multiplies the contents stored in the net weight register 11 and the contents stored in the unit price register 14, and outputs the contents of the fee corresponding to the net weight. The fee details calculated by the fee calculation circuit 12 are supplied to the fee register 15 and further supplied to the display section 8 via the gate 7.

Further, in the above configuration, the gate 5 for transferring the contents of the weight register 3 to the tare register 6 and the contents of the net weight calculation circuit 4 are transferred directly to the net weight register 11 through the auto-zero circuit 10 or without passing through the auto-zero circuit. The control signal supplied to the gate 9 for transfer to the tare bag is outputted from the tare control section 17 by operating the tare key 16. The gate 9 and the auto-zero circuit 10 are controlled by operating the auto-zero switch 18, so that the scale can be used as an electronic digital scale with the auto-zero function always disabled.

Next, the operation of the circuit having the above configuration will be specifically explained.

First, if there is no object to be weighed on the weighing platform,
The data content of the weight corresponding to the wobbling of the weighing platform, etc., which is supplied to the weight register 3, is supplied to the net weight calculation circuit 4, and the content of the tare register 6 (assuming that the initial state of zero is input at this time). Subtraction processing is performed between the two and the result is supplied to the auto-zero circuit 10. Then, the contents supplied to the net weight register 11 are set to zero by the auto-zero circuit 10 when the weight corresponding to the above-mentioned fluctuation is within the operating range of the auto-zero function, so the content is displayed on the display section. There is no fluctuation and zero is displayed.

Next, in order to perform the tare operation, for example, 3g
When the tare key 16 is operated after placing a heavy tare on the weighing table, the contents 3g stored in the weight register 3 are supplied to the tare register 6 via the gate 5. The content 3g of the weight register 3 and the content 3g of the tare register 6 are subtracted in the net weight calculation circuit 4, and the result of this calculation, 0g, is directly supplied to the net weight register 11 via the gate 9. At this time, the content 3g of the tare weight register 6 and the content 0g of the net weight register are both displayed on the display section 8 via the gate 7. During tare operation,
For example, when the tare on the weighing platform is removed, the weight register 3 becomes 0 g, so the net weight calculation circuit 4 subtracts the 3 g content of the tare register 6 from the 0 g content of the weight register 3, and adds -3 g to the net weight register 11. It is directly supplied and -3g is displayed on the display section 8 through the gate 7. Furthermore, in this state, if an object to be weighed weighing 1 g is placed on the scale together with a tare bag, the weight register 3 receives 4 g, which is the sum of the weight of the object to be weighed, 1 g, and the weight of the tare bag, 3 g, and the net weight calculation circuit 4g of weight register 3 at 4
3g of the tare weight register 6 is subtracted from the net weight register 6, and 1g of this calculation result is directly supplied to the net weight register 11. Then, the net weight of 1 g is displayed on the display section 8 via the gate 7.

That is, in the tare subtraction operation, the operation of the auto-zero circuit 10 is canceled by operating the tare key 16, and the calculation result of the net weight calculation circuit 4 is always supplied directly to the net weight register 11 via the gate 9. It is something that is done. Further, in order to complete the tare subtraction operation, the tare key 16 is operated again to clear the contents of the tare register 6 and return it to its initial state, and the auto-zero circuit 10 is activated.

In the above-described operation, the case where the tare is placed on the weighing stand and its weight is input into the tare register 6 is explained, Direct input is also possible.

Of course, the specific configuration of each circuit in the above-mentioned embodiments is not limited in any way and is arbitrary, and in addition to the hardware circuit configuration, it is also possible to configure it in software as a means to perform the same function and control it by a computer. It's okay.

As explained above, this invention is an electronic digital scale with an auto-zero function. You can cancel the auto zero function and set the tare weight.

Therefore, when setting the tare weight, there is no need to take the trouble to operate the auto-zero release switch to stop the auto-zero function, making it extremely easy to set the tare weight.

[Brief explanation of drawings]

The drawing is a block diagram of an electronic digital scale showing an embodiment of this invention. 3... Weight register, 4... Net weight calculation circuit, 6... Tare register, 9... Gate circuit, 1
0...Auto zero circuit, 16...Tare key.

Claims (1)

[Scope of claim for utility model registration] An electronic digital scale that digitally displays the weight of an object to be weighed on a display, which includes a weight register that stores the weight of the object to be weighed, and a tare key that is operated when setting the tare weight. a tare register that stores the weight of the object to be weighed as a tare weight when the tare key is operated; and a tare weight stored in the tare register based on the weight of the object to be weighed stored in the weight register. net weight calculation means that calculates the net weight of the object to be weighed by subtracting and a control means for canceling the operation of the auto-zero means and displaying the calculated net weight as is when the tare key is operated and the tare weight is set while the auto-zero means is in operation. An auto-zero control device for an electronic digital scale, characterized by comprising: